NATE Air Conditioning Specialty
Certification Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A Instant Download
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1. What is the primary purpose of superheat measurement in an air-
conditioning system?
A. To determine condenser airflow
B. To determine evaporator refrigerant condition
C. To measure compressor amperage
D. To determine condenser subcooling
Answer: To determine evaporator refrigerant condition
Rationale: Superheat indicates how much the refrigerant vapor temperature
exceeds its saturation temperature. It is especially useful for evaluating
evaporator feeding and refrigerant charge.
2. What does subcooling indicate?
A. The temperature of superheated vapor
B. The amount liquid refrigerant temperature is below its saturation temperature
C. The compressor compression ratio
D. The evaporator airflow
,Answer: The amount liquid refrigerant temperature is below its saturation
temperature
Rationale: Subcooling is the difference between the refrigerant's saturation
temperature and actual liquid-line temperature.
3. Which instrument is normally used to measure refrigerant pressure?
A. Psychrometer
B. Manifold gauge set
C. Clamp meter
D. Micrometer
Answer: Manifold gauge set
Rationale: A manifold gauge set provides access to system pressure and allows
the technician to evaluate suction and discharge conditions.
4. What is the saturation temperature of a refrigerant?
A. The temperature at which oil boils
B. The temperature corresponding to a specific refrigerant pressure at phase
change
C. The outdoor-air temperature
D. The compressor discharge temperature
Answer: The temperature corresponding to a specific refrigerant pressure at
phase change
Rationale: Refrigerant pressure-temperature relationships allow technicians to
determine saturation temperature from measured pressure.
5. What is the main purpose of a filter-drier?
A. Increase compressor horsepower
B. Remove moisture and contaminants from the refrigerant circuit
C. Increase airflow
D. Reduce thermostat voltage
,Answer: Remove moisture and contaminants from the refrigerant circuit
Rationale: Filter-driers protect the system by trapping contaminants and
absorbing moisture that can damage components or create acids.
6. What condition can excessive moisture in a refrigeration system cause?
A. Improved heat transfer
B. Acid formation and possible freezing at restrictions
C. Increased blower speed
D. Lower electrical resistance
Answer: Acid formation and possible freezing at restrictions
Rationale: Moisture can react with refrigerant and oil to form acids and may
freeze at expansion devices or other restrictions.
7. Which component removes heat from indoor air?
A. Condenser
B. Evaporator
C. Compressor
D. Receiver
Answer: Evaporator
Rationale: The evaporator absorbs heat from the conditioned space as
refrigerant changes from liquid to vapor.
8. Which component rejects heat to the outdoor environment?
A. Evaporator
B. Condenser
C. Metering device
D. Accumulator
Answer: Condenser
, Rationale: The condenser removes heat from the refrigerant and transfers it to
outdoor air or another heat-transfer medium.
9. What is the primary function of the compressor?
A. Meter refrigerant
B. Raise refrigerant vapor pressure and circulate refrigerant
C. Remove moisture
D. Measure airflow
Answer: Raise refrigerant vapor pressure and circulate refrigerant
Rationale: The compressor draws low-pressure vapor from the evaporator and
compresses it into high-pressure vapor for the condenser.
10. What is the primary function of a metering device?
A. Increase condenser airflow
B. Control refrigerant flow into the evaporator and create a pressure drop
C. Increase compressor oil level
D. Remove noncondensables
Answer: Control refrigerant flow into the evaporator and create a pressure drop
Rationale: The metering device regulates refrigerant entering the evaporator
and establishes the pressure difference required for evaporation.
11. Which device is designed to maintain a controlled evaporator superheat?
A. Fixed orifice
B. Thermostatic expansion valve
C. Service valve
D. Receiver
Answer: Thermostatic expansion valve
Rationale: A TXV modulates refrigerant flow based primarily on evaporator
outlet superheat.
Certification Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A Instant Download
1. What is the primary purpose of superheat measurement in an air-
conditioning system?
A. To determine condenser airflow
B. To determine evaporator refrigerant condition
C. To measure compressor amperage
D. To determine condenser subcooling
Answer: To determine evaporator refrigerant condition
Rationale: Superheat indicates how much the refrigerant vapor temperature
exceeds its saturation temperature. It is especially useful for evaluating
evaporator feeding and refrigerant charge.
2. What does subcooling indicate?
A. The temperature of superheated vapor
B. The amount liquid refrigerant temperature is below its saturation temperature
C. The compressor compression ratio
D. The evaporator airflow
,Answer: The amount liquid refrigerant temperature is below its saturation
temperature
Rationale: Subcooling is the difference between the refrigerant's saturation
temperature and actual liquid-line temperature.
3. Which instrument is normally used to measure refrigerant pressure?
A. Psychrometer
B. Manifold gauge set
C. Clamp meter
D. Micrometer
Answer: Manifold gauge set
Rationale: A manifold gauge set provides access to system pressure and allows
the technician to evaluate suction and discharge conditions.
4. What is the saturation temperature of a refrigerant?
A. The temperature at which oil boils
B. The temperature corresponding to a specific refrigerant pressure at phase
change
C. The outdoor-air temperature
D. The compressor discharge temperature
Answer: The temperature corresponding to a specific refrigerant pressure at
phase change
Rationale: Refrigerant pressure-temperature relationships allow technicians to
determine saturation temperature from measured pressure.
5. What is the main purpose of a filter-drier?
A. Increase compressor horsepower
B. Remove moisture and contaminants from the refrigerant circuit
C. Increase airflow
D. Reduce thermostat voltage
,Answer: Remove moisture and contaminants from the refrigerant circuit
Rationale: Filter-driers protect the system by trapping contaminants and
absorbing moisture that can damage components or create acids.
6. What condition can excessive moisture in a refrigeration system cause?
A. Improved heat transfer
B. Acid formation and possible freezing at restrictions
C. Increased blower speed
D. Lower electrical resistance
Answer: Acid formation and possible freezing at restrictions
Rationale: Moisture can react with refrigerant and oil to form acids and may
freeze at expansion devices or other restrictions.
7. Which component removes heat from indoor air?
A. Condenser
B. Evaporator
C. Compressor
D. Receiver
Answer: Evaporator
Rationale: The evaporator absorbs heat from the conditioned space as
refrigerant changes from liquid to vapor.
8. Which component rejects heat to the outdoor environment?
A. Evaporator
B. Condenser
C. Metering device
D. Accumulator
Answer: Condenser
, Rationale: The condenser removes heat from the refrigerant and transfers it to
outdoor air or another heat-transfer medium.
9. What is the primary function of the compressor?
A. Meter refrigerant
B. Raise refrigerant vapor pressure and circulate refrigerant
C. Remove moisture
D. Measure airflow
Answer: Raise refrigerant vapor pressure and circulate refrigerant
Rationale: The compressor draws low-pressure vapor from the evaporator and
compresses it into high-pressure vapor for the condenser.
10. What is the primary function of a metering device?
A. Increase condenser airflow
B. Control refrigerant flow into the evaporator and create a pressure drop
C. Increase compressor oil level
D. Remove noncondensables
Answer: Control refrigerant flow into the evaporator and create a pressure drop
Rationale: The metering device regulates refrigerant entering the evaporator
and establishes the pressure difference required for evaporation.
11. Which device is designed to maintain a controlled evaporator superheat?
A. Fixed orifice
B. Thermostatic expansion valve
C. Service valve
D. Receiver
Answer: Thermostatic expansion valve
Rationale: A TXV modulates refrigerant flow based primarily on evaporator
outlet superheat.
